Zhuo Shuo, Shu Hieng Tie Billy, Keane Gavin, Geever Luke M
Polymer, Recycling, Industrial, Sustainability and Manufacturing Center (PRISM), Technological University of the Shannon: Midlands Midwest, Dublin Road, N37 HD68 Athlone, Ireland.
Centre for Industrial Service & Design, Technological University of the Shannon: Midlands Midwest, Dublin Road, N37 HD68 Athlone, Ireland.
Polymers (Basel). 2023 Mar 18;15(6):1511. doi: 10.3390/polym15061511.
Stimuli-responsive hydrogels are one type of smart hydrogel, which can expand/contract in water according to changes in the surrounding environment. However, it is difficult to develop flexible shapeshifting behaviours by using a single hydrogel material. This study exploited a new method to utilise single and bilayer structures to allow hydrogel-based materials to exhibit controllable shape-shifting behaviours. Although other studies have demonstrated similar transformation behaviours, this is the first report of such smart materials developed using photopolymerised N-vinyl caprolactam (NVCL)-based polymers. Our contribution provides a straightforward method in the fabrication of deformable structures. In the presence of water, the bending behaviours (vertex-to-vertex and edge-to-edge) were achieved in monolayer squares. By controlling the content and combination of the NVCL solutions with elastic resin, the bilayer strips were prepared. The expected reversible self-bending and self-helixing behaviours were achieved in specific types of samples. In addition, by limiting the expansion time of the bilayer, the layered flower samples exhibited predictable self-curving shape transformation behaviour in at least three cycles of testing. These structures displayed the capacity of self-transformation, and the value and functionality of the produced components are reflected in this paper.
刺激响应性水凝胶是一类智能水凝胶，它能够根据周围环境的变化在水中膨胀/收缩。然而，使用单一水凝胶材料很难实现灵活的形状转变行为。本研究开发了一种新方法，利用单层和双层结构使水凝胶基材料展现出可控的形状转变行为。尽管其他研究已经证明了类似的转变行为，但这是首次报道使用基于光聚合N-乙烯基己内酰胺（NVCL）的聚合物开发出的此类智能材料。我们的贡献为可变形结构的制造提供了一种直接的方法。在有水的情况下，单层正方形实现了弯曲行为（顶点到顶点和边缘到边缘）。通过控制NVCL溶液与弹性树脂的含量和组合，制备了双层条带。在特定类型的样品中实现了预期的可逆自弯曲和自螺旋行为。此外，通过限制双层的膨胀时间，层状花朵样品在至少三个测试循环中表现出可预测的自弯曲形状转变行为。这些结构展示了自我转变的能力，本文还体现了所制备组件的价值和功能。
